柴达木盆地退化弃耕地紫花苜蓿地上生物量动态

The Seasonal Dynamics of the Biomass of Medicago sativa in the Degenerated and Abandoned Arable in Chaidamu Basin.

在柴达木盆地退化弃耕地上用紫花苜蓿建立人工草地恢复植被效果良好 ,二龄紫花苜蓿地上生物量及群落地上生物量季节变化呈“S”型曲线 ,其高峰期在 8月底。紫花苜蓿、野生杂类草和群落生物量生长速率季节动态不尽相同 ,紫花苜蓿种群和群落生物量生长速率的最大值在 7～ 8月份 ,野生杂类草最大值在 6～ 7月份。播种当年采用紫花苜蓿 +燕麦混播处理不仅可提高紫花苜蓿新生苗的存活率和越冬率 ,而且使第 2年返青出苗整齐 ,地上生物量较单播提高 3 1.82 % 。

There are artificial grassland of Medicago sativa in the degenerated and abandoned arable in Chaidamu basin. The recovered result of vegetation is good. The aboveground biomass of the second year Medicago sativa and the seasonal change of aboveground biomass of community all showed 'S' curve, and the top of growth period is at the end of the August. The growth rate in different season of Medicago sativa, forbs and community biomass is different. The period of the maximum growth rate of Medicago sativa and community biomass is in the July August, and that of forbs is in the June July. The mixed sowing of Medicago sativa with Avena sativa notoely improves the living rate and overwintering rate of Medicago sativa seedling but also increases aboveground biomass by 31.82% than that of single sowing, and improve benefits of the same year.